High resilience cold cured slabstock or molded polyether urethane foams have been prepared heretofore in which the conventional "hot cure" cycle required previously to effect completion of the urethane reaction in foam formulation has been eliminated and lower molding costs and faster cycles secured. The additional advantages of significantly high resilience and load ratio, high tensile strength, higher elongation and greater tear strength together with significant improvements in hystersis and fatigue have caused a demand for these foams particularly in furniture, bedding applications, and in automotive deep molded seat cushioning. These applications of high resilience foams render the flammability and smoke emission properties of these foams of particular relevance and indeed the subject of governmental concern and regulation. While high resilience foams are known to have certain fire retardant properties, a further substantial enhancement of the self-extinguishing and non-burning characteristics of these foams without an adverse effect on the other and improved properties referred to in the foregoing discussion would fulfil a felt need, particularly where achieved with concomitant improvements in the process of manufacture of the foam.
In this latter context, it has been known heretofore to use 4,4'-methylene-bis(2-chloraniline) as a chain extender in the preparation of these high resilience foams; a practice which has been discouraged by further governmental regulations resulting from properties of this compound considered harmful to personnel in the concentrations ordinarily required in foam preparation. Efforts to replace this compound, in whole or in part with other materials, for example, saturated glycols such as 1,4-butanediol, have only been partially successful and neither the glycols, nor the aniline that it is proposed to displace, impart a significantly enhanced self-extinguishing and non-burning property to the foam.
Accordingly, if the flammability of high resilience cold cured flexible polyether urethane foams could be measurably improved, the qualities normally inhering in high quality, high resilience foams retained, and 4,4'-methylene bis(2-chloroaniline) replaced in the formulation of these foams, in an inexpensive manner, a significant advance in the state of the art would be achieved.